In older versions of the Magento system, problems can still occur in some cases when calculating totals and taxes, resulting in a rounding-related discrepancy of 1 cent.
This can be resolved by modifying the file \app\code\local\Mage\Core\Model\Store.php, which should first be copied from the file \app\code\core\Mage\Core\Model\Store.php to avoid making changes directly to core files:
Simply change the rounding at this point:
public function roundPrice($price)
{
return round($price, 2);
}
from 2 to 4 decimal places:
public function roundPrice($price)
{
return round($price, 4);
}
Seen in Magento 1.7.0.2.
